A new study from the Society of Actuaries says that a third of adults do not expect to retire. Not so surprising. But, what is is that this number is up 29% from two yeas ago and, yes, this increase is significant.

Many people, more than 4 in 10 say that they cannot retire because they need the bucks and, in many cases, the employer benefits.

Uncertainty – about life-expectancy and the money required to cover long-term living expenses – also plays a major role in per-retirement planning.

“Current trends in retirement indicate that people may need to work longer than they originally planned,” said actuary and retirement expert Carol Bogosian, ASA. “Individuals often have a difficult time estimating how long they can expect to live, how much they will earn on their investments and how much they can spend each year to avoid running out of money. In fact, many people are just guessing about how much money they will need in retirement.”

There is, of course, another reason. We might not want to stop working.